The present invention concerns a device and process for monitoring the condition of the tires of a vehicle as well as of their environment, particularly the temperature of the braking mechanisms.
Numerous known devices for monitoring the condition of the tires of a vehicle are not content with activating an alarm when the pressure of one of the tires is lower than a given threshold, but transmit continuously to a central unit connected to a display device situated close to the driver the internal pressure of the tires as well as, for some of them, the internal temperature of the said tires. Such a device is described, for example, in the application WO89/05737.
Intensive usage of the brakes or defective functioning of the brakes leads to very significant heat build-up of the braking mechanisms in friction (disk-caliper or drum-brake shoes). This heat build-up can lead directly to serious damage to the braking. On the other hand, this heat build-up is transmitted to all of the mechanical parts located near these braking mechanisms and particularly to the tires through their rims. Consequently, the heat build-up of the braking mechanisms disturbs the measurements of inflation pressure and temperature done by the systems for monitoring the condition of these tires, but also can be the cause of thermic fatigue of the parts of the tires in contact with the rims.
It is therefore very important to be able to detect an abnormal heat build-up of these braking mechanisms. U.S. Pat. No. 5,050,110 proposes, in order to correct the errors due to heat build-up of the braking mechanisms, to situate near these braking mechanisms a temperature sensor as a complement to those which measure the internal temperature of the tires. This device can, of course, detect an abnormal heat build-up of the braking mechanisms. But, it requires increasing the number of sensors of measurement in the vehicle, which is costly.